this is what they guy said on ebay
The bones of the bike, Frame and motor are 1984 the rear of the frame to hold the seat and guard has been modified the swingarm is offset, the right side foot peg is set lower and further back than the left, one fork leg is shorter and stiffer than the other,as you can see it has one Olins shock on the left side this is how ATK flattrackers are set up hope this helps
Cheers John